Motion control device for guide rails of drawers

ABSTRACT

A motion control device ( 1 ) for guide rails of drawers comprising a carcass rail ( 2 ), a drawer rail ( 4 ) and a central rail ( 3 ) arranged between those two rails ( 2, 4 ) at both sides of the drawer, wherein the load of the drawer is transmitted by rollers ( 6, 6′, 15, 15′ ) which are preferably arranged in carriages, characterised in that the motion control device ( 1 ) has a releasable coupling device ( 9 ) between at least one roller ( 6, 6′ ) and the carcass rail ( 2 ).

The present invention relates to a motion control device for guide rails of drawers comprising a carcass rail, a drawer rail and a central rail arranged between those two rails at both sides of the drawer, wherein the load of the drawer is transmitted by rollers which are preferably arranged in carriages.

Usually rollers of that kind are arranged in a carriage which is disposed displaceably between the guide rails of the drawer. Due to the slippage between the rollers and the guide rails, that design configuration does not always ensure that, when the drawer is pulled out and pushed in, the carriages exactly cover half the distance of the pull-out rails. That gives rise to what are referred to as carriage errors, that is to say the position of the carriages is not correct in relation to the support and pull-out rails. Carriage errors of that kind can under some circumstances result in the drawer remaining open in normal use.

The problems with carriage errors of that kind are known in accordance with the state of the art and repeatedly occur in pull-out guide fitments in which the load is carried by rollers which are not mounted to the rails but in separate carriages. If the drawer is moved exclusively manually, in many cases those errors are not noticed. If the drawer is pulled into the definitive closed position by a conventional closing system with springs, then in most cases there is so much momentum that the carriage error is corrected by the dynamics of the drawer and the drawer always closes.

Modern extension guide arrangements for drawers have closing devices which are additionally fitted with a damper so that the drawer is not pulled into the body of furniture with too much momentum. Those dampers however reduce the closing dynamics of the drawer to such an extent that a carriage error which has occurred during the movement of the drawer can no longer be compensated, due to the lack of kinetic energy.

One solution for overcoming those problems is described for example in the applicants' Austrian utility model AT 6 528 U1. That structure has a motion control device formed for example by cables. That motion control device determines the movements of the carriage in relation to the support rail and/or the pull-out or extension rail. The provision of a motion control device of that kind however requires a relatively high level of structural complication and expenditure.

Therefore the object of the present invention is to improve a motion control device of the general kind set forth in the opening part of this specification, such that synchronisation errors in respect of the rollers or the carriage are corrected and thus correct closing and opening of the drawer is achieved, with the structural complication and expenditure being minimised.

The object according to the invention is attained in that the motion control device comprises a releasable coupling device between at least one roller and the carcass rail.

By virtue of the arrangement of the releasable coupling device between at least one roller and the carcass rail, the central rail which rests on the rollers can be moved only upon the fulfilment of a basic condition, preferably when the drawer rail is in a given position relative to the central rail. In that respect a preferred embodiment of the invention provides that upon closure of the drawer rail the releasable coupling device firstly holds fast the central rail which is fully extended relative to the carcass rail and only releases the central rail as soon as the drawer rail is completely retracted relative to the central rail.

In other words the releasable coupling device ensures that, in the closing procedure, firstly the central rail/carcass rail assembly is stationary—preferably in the completely open position relative to each other—and only the drawer rail is displaceable relative to the central rail. When the drawer rail is fully retracted in relation to the central rail, the central rail/drawer rail assembly can be entirely retracted relative to the carcass rail.

The term ‘rollers’ is to be viewed as a broad term in the context of the invention and, besides actual load-bearing rollers, includes all rollers, rolling bodies, balls, discs and so forth which can be used for that purpose.

There are various possible options from the structural point of view, for implementation of the releasable coupling device. For reasons of simplicity, the design configuration can be such that the releasable coupling device comprises in the running surface of the carcass rail a trough or a recess for temporarily receiving at least one roller. In that case it may be desirable if the trough or recess is of such a dimension that precisely one roller is received on a part of its diameter in the trough or in the recess. In order to improve the effect of holding the roller fast in the trough or in the recess, it can be advantageous if the trough or the recess is arranged transversely with respect to the direction of travel of the roller or rollers on the carcass rail. It is particularly desirable if the trough or the recess is arranged in the front end region of the carcass rail. If a trough is provided as part of the releasable coupling device, it is desirable if the roller bears at at least a part of its surface in surface contact against the trough. The variant with a recess as part of the releasable coupling device is particularly simple to implement, from the point of view of structural engineering. In the production procedure the recess can be simply stamped into the running surface of the carcass rail, in which case the size can be such that the roller bears against the edges of the recess.

For an advantageous motion control of the above-specified rails in the opening procedure, in accordance with a further variant of the invention there is provided a further motion control device. That motion control device for guide rails of drawers includes a carcass rail, a drawer rail and a central rail arranged between those two rails at both sides of the drawer, wherein the load of the drawer is transmitted by rollers, preferably by carriages. That motion control device is characterised in that the motion control device has a releasable coupling device between at least one roller and the drawer rail.

By virtue of the arrangement of a releasable coupling device between at least one roller and the drawer rail, in the opening procedure the drawer rail which is mounted on the rollers can be moved only upon the fulfilment of a further basic condition, preferably when the central rail is in a given position relative to the carcass rail. In that respect a preferred embodiment of the invention provides that upon opening of the drawer rail the releasable coupling device firstly entrains the central rail and releases the drawer rail only when the central rail is fully extended.

In other words the releasable coupling device ensures that, in the drawer opening procedure, firstly the drawer rail/central rail assembly is moved from its closed position until the condition of abutment of the central rail in relation to the carcass rail and it is only subsequently thereto that the drawer rail can be moved relative to the central rail.

There are various possible options from the structural point of view in regard to implementation of the releasable coupling device between the roller or rollers and the drawer rail. For the sake of a simple structural configuration however it can more advantageously be provided that the releasable coupling device includes a resilient hook which is temporarily latchable into a depression. As a preferred embodiment provides for the use of carriages, it can desirably be provided that the hook is arranged or formed on a carriage which is displaceable between the central rail and the drawer rail.

Since—as already mentioned—the term ‘roller’ is to be interpreted in the broadest sense, it can also be provided that the roller or rollers is or are in the form of cylindrical roller or rollers. Likewise a variant is included, which provides that the roller or rollers is or are in the form of a ball or balls. In that respect it may be advantageous if the roller or rollers is or are formed from an elastically deformable material or has or have a casing comprising an elastically deformable material.

Alternatively or supplemental to the above-mentioned material the configuration can be such that at least one roller and/or at least one ball can be pressed into the trough or into the recess by a spring-loaded spindle extending transversely with respect to the direction of travel of the roller and/or ball. The roller disposed in the trough or recess can be more heavily loaded thereby, whereby the application of force which is required for the user to move the drawer is increased. The spring loading can be selected in dependence on the drawer size or the weight of the drawer, having regard to the load therein. Desirably the pressure prestressing of the spring-loaded spindle can be adapted to be adjustable.

Finally it is advantageously provided that at least two rollers are arranged on the carcass rail and/or on the central rail in at least one displaceable carriage.

Further details and advantages of the present invention will be described in greater detail hereinafter by means of the specific description with reference to the drawings in which:

FIG. 1 shows a diagrammatic side view of a motion control device according to the invention with carcass rail, central rail and drawer rail in the open position,

FIG. 2 shows the motion control device of FIG. 1 with fully retracted drawer rail in relation to the central rail and detail views of the two releasable coupling devices,

FIG. 3 shows the motion control device of FIGS. 1 and 2 in the completely closed position,

FIG. 4 is a diagrammatic perspective view of an extension guide fitment with a recess on the carcass rail,

FIG. 5 shows the extension guide fitment of FIG. 4 in an exploded condition with a plurality of detail views,

FIG. 6 shows an extension guide fitment with a trough as part of the first releasable coupling device, and

FIGS. 7 a-7 c is a diagrammatically illustrated time succession of the positions of the rollers in the opening movement.

FIG. 1 is a diagrammatically illustrated side view of the motion control device 1 which includes a carcass rail 2, a central rail 3 and a drawer rail 4. The carcass rail 2 is fixedly secured in conventional manner to the side wall of a body of furniture, and the drawer rail 4 is fixedly screwed to a drawer. The load of the drawer is transmitted on the one hand by rollers 6, 6′ arranged in a carriage 5. The carriage 5 is arranged displaceably between the carcass rail 2 and the central rail 3. On the other hand the load of the drawer is also transmitted by further carriages 7, 8 arranged between the central rail 3 and the drawer rail 4. The illustrated arrangement shows the open position of the rails 2, 3 and 4 and in that respect corresponds to the state of the art. The problem in the state of the art is that the slippage between the carriages 5, 7, 8 and the rails 3, 4 means that there is no guarantee that, when pulling the rails 3, 4 out and in, the carriages 5, 7, 8 cover exactly half the distance in relation to the central rail 3 and the drawer rail 4 respectively. That gives rise to what are referred to as carriage errors, that is to say the carriages 5, 7, 8 are not correct in relation to the rails 2, 3, 4. That fact can result in the drawer remaining open, particularly in conjunction with additional damping devices. In order to permit correct opening and closing of the drawer with simple structural means, there is provided a first and a second releasable coupling device 9, 10 which are to be described in further detail in the Figures hereinafter.

FIG. 2 shows the motion control device from FIG. 1, with the drawer rail 4 being disposed in a fully retracted position relative to the central rail 3. So that the central rail 3 does not move in relation to the carcass rail 2 upon displacement of the drawer rail 4, there is provided a first releasable coupling device 9 which is shown on an enlarged scale in the detail view D2. Upon closing the drawer rail 4, that first releasable coupling device 9 firstly holds fast the central rail 3 which is fully extended relative to the carcass rail 2, and releases the central rail 3 only as soon as the drawer rail 4 is fully retracted relative to the central rail 3. In the illustrated view the first releasable coupling device 9 includes a trough 11 or recess 11′ which is arranged in the running surface of the carcass rail 2. The trough 11 serves for temporarily receiving at least one roller 6′ which is of such a size that the roller 6′ is received therein, on a part of its diameter. The trough 11 is disposed in the front region of the carcass rail 2 and is preferably arranged transversely with respect to the direction of travel of the carriage 5 or the rollers 6, 6′. When the frontmost roller 6′ is received in the trough 11, the behind rollers 6′ are more heavily loaded, which is also governed by the lever effect which occurs when the drawer is laden. Therefore a greater amount of force needs to be applied in order to move the central rail 3 relative to the carcass rail 2. In the closing movement, firstly only the drawer rail 4 moves relative to the central rail 3 until an abutment (not shown) marks the completely closed position of the central rail 3. That position is shown in FIG. 2. Starting from that position the central rail/drawer rail assembly can now be moved by additionally exerted pressure into the definitive closed position.

In order to permit proper positioning of the carriages 7, 8 in the opening movement of the drawer rail 4 in relation to the central rail 3, a second releasable coupling device 10 is illustrated. In the illustrated Figure the second releasable coupling device 10 is arranged or formed on the carriage 8 which is arranged displaceably between the drawer rail 4 and the central rail 3. The releasable coupling device 10 is shown on an enlarged scale in the detail view D1 in FIG. 2. The second releasable coupling device 10 includes a resilient or spring-loaded hook 12 which is temporarily latchable in a depression 13, the depression 13 being arranged or formed at the underside of the drawer rail 4. That second releasable coupling device 10 ensures that, upon opening of the drawer rail 4, firstly the central rail 3 is entrained and it is only when the central rail 3 is fully extended that the drawer rail 4 is released. If the starting point is the closed position shown in FIG. 3, then the central rail 3/drawer rail 4 assembly is displaced jointly relative to the carcass rail 2 by the latched hook 12 until the roller 6′ is received in the trough 11. If a pull is further applied to the drawer rail 4, the resilient hook 12 is disengaged from the depression 13 and—as shown in FIG. 1—the drawer rail 4 can also be displaced relative to the central rail 3. FIG. 3 shows the completely closed position of the rails 2, 3, 4. Starting from that position, it is possible to implement the opening movement in a time sequence of FIG. 3-FIG. 2-FIG. 1.

FIG. 4 shows a perspective view by way of example of an extension guide fitment 14 with the motion control device 1 according to the invention. In the illustrated Figure the fitment 14 includes a recess 11′ arranged at the running surface of the carcass rail 2. The recess 11′ is arranged in the front end region of the carcass rail 2 and extends transversely with respect to the direction of travel of the rollers 6, 6′. In the completely open position of the central rail 3, relative to the carcass rail 2, the rollers 6′ bear against the edges of the recess 11′. The central rail 3 can optionally also be omitted so that only the drawer rail 4 is displaceable on rollers 6, 6′ or on carriages 5 along the carcass rail 2. The design configuration with the recess 11′ is particularly simple from the point of view of structural engineering as it can be produced by an uncomplicated stamping operation.

FIG. 5 is an exploded view of the extension guide fitment 14 of FIG. 4, together with a number of detail views D3 to D6 on an enlarged scale. The carcass rail 2 is fixedly screwed to a side wall of the body of furniture in the usual way. Detail view D3 shows the recess 11′ in the running surface of the carcass rail 2. At least one carriage 5 is arranged displaceably on that running surface of the carcass rail 2. Detail view D4 shows the rollers 6′ of the carriage 5, wherein the foremost is received in the recess 11 as it occupies a lower position than the other rollers 6′. The other rollers 6′ are more heavily loaded thereby, whereby an increased amount of force needs to be applied to move the carriage 5 out of the recess 11′. Two further carriages 7 and 8 are arranged displaceably on the running surface of the central rail 5, those carriages 7, 8 having both horizontal rollers 15 and vertical rollers 15′. The drawer rail 4 is in turn supported on those two carriages 7, 8.

FIG. 6 shows the extension guide fitment 14 with a concave trough 11 as part of the first releasable coupling device 1. The detail view D7 shows that region of the carcass rail 2 on an enlarged scale. The trough 11 serves for temporarily receiving at least one roller 6′ for releasably fixing the central rail 3 relative to the carcass rail 2.

FIGS. 7 a to 7 c diagrammatically show a time sequence of the rollers 6′ which are arranged movably between the carcass rail 2 and the central rail 3. In FIG. 7 a all rollers 6′ are disposed outside the trough 11. If the central rail 3 is displaced further in relation to the carcass rail 2, the foremost one of the rollers 6′ is received at at least a part of its surface in surface contact in the trough 11, as is shown in FIG. 7 c. It is preferably provided that the rollers 6′ are formed from an elastically deformable material or have a coating of an elastically deformable material. The pressure of the roller 6′ in the direction of the trough 11 can be increased if they are urged into the trough 11 by a spring-loaded spindle extending transversely with respect to the direction of travel thereof.

The invention is not limited to the illustrated embodiments by way of example but extends to or embraces all technical equivalents which can fall within the scope of the claims hereinafter. The positional information selected in the description, such as for example top, bottom, lateral and so forth is also related to the directly described and illustrated Figure and upon a change in position is to be correspondingly transposed to the new position. The trough 11 or the recess 11′ can basically be produced by the most widely varying cutting or non-cutting production processes such as for example by punching, stamping, milling or the like. 

1. A motion control device for guide rails of drawers comprising a carcass rail, a drawer rail and a central rail arranged between those two rails at both sides of the drawer, wherein the load of the drawer is transmitted by rollers, characterised in that the motion control device comprises a releasable coupling device between at least one roller and the carcass rail.
 2. A motion control device according to claim 1, characterised in that the rollers are arranged in carriages.
 3. A motion control device according to claim 1 characterised in that upon closure of the drawer rail, the releasable coupling device firstly holds fast the central rail which is fully extended relative to the carcass rail and only releases the central rail as soon as the drawer rail is completely retracted relative to the central rail.
 4. A motion control device according to claim 1 characterised in that the releasable coupling device comprises in the running surface of the carcass rail a trough or a recess for temporarily receiving at least one roller.
 5. A motion control device according to claim 4 characterised in that the trough or recess is of such a dimension that precisely one roller is received on a part of its diameter in the trough or in the recess.
 6. A motion control device according to claim 4 characterised in that the trough or the recess is arranged transversely with respect to the direction of travel of the roller or roller on the carcass rail.
 7. A motion control device according to claim 4 characterised in that the trough or the recess is arranged in the front end region of the carcass rail.
 8. A motion control device according to claim 4 characterised in that the roller bears at at least a part of its surface in surface contact against the trough.
 9. A motion control device according to claim 4 characterised in that the roller bears against the edges of the recess.
 10. A motion control device for guide rails of drawers comprising a carcass rail, a drawer rail and a central rail arranged between those two rails at both sides of the drawer, wherein the load of the drawer is transmitted by rollers, characterised in that the motion control device has a releasable coupling device between at least one roller and the drawer rail.
 11. A motion control device according to claim 10 characterised in that the rollers are arranged in carriages.
 12. A motion control device according to claim 10 characterised in that upon opening of the drawer rail the releasable coupling device firstly entrains the central rail and releases the drawer rail only when the central rail is fully extended.
 13. A motion control device according to claim 10 characterised in that the releasable coupling device comprises a resilient hook which is temporarily latchable into a depression.
 14. A motion control device according to claim 13 characterised in that the hook is arranged or formed on a carriage displaceable between the central rail and the drawer rail.
 15. A motion control device according to claim 1 characterised in that the roller or rollers is or are in the form of a cylindrical roller or rollers.
 16. A motion control device according to claim 1 characterised in that the roller or rollers is or are in the form of a ball or balls.
 17. A motion control device according to claim 1 characterised in that the roller or rollers is or are formed from an elastically deformable material or has or have a casing comprising an elastically deformable material.
 18. A motion control device according to claim 1 characterised in that at least one rollers and/or at least one ball can be pressed into the trough or into the recess by a spring-loaded spindle extending transversely with respect to the direction of travel of the roller and/or ball.
 19. A motion control device according to claim 1 characterised in that at least two rollers are arranged on the carcass rail and/or on the central rail in a displaceable carriage. 